// function identify(context){
//   return context.name.toUpperCase()
// }

function identify(){
    return this.name.toUpperCase()
  }

// function speak(context){
//     var greeting = "hello, I'm" +  identify(context)
//     console.log(greeting);
// }

function speak(){
    var greeting = "hello, I'm" +  identify.call(this)
    console.log(greeting);
}

var me = {
    name: 'wn'
}
var you = {
    name: 'az'
}

// let result = identify.call(me)  //call把identify的作用域指向me
// let result2 = identify.call(you)
// console.log(result);
// console.log(result2);
speak.call(me)

// console.log(identify(me));
// speak(me)